The Flashback Bomb: The Nuke that Time Forgot

The Flashback Bomb: The Nuke that Time Forgot

by Aden Tate

The Flashback Bomb is the forgotten nuke. Everybody knows about Fat Man and Little Boy. Students of nuclear warfare history likely know about the Tsar Bomba as well. But only a few have ever heard of the United States' most powerful nuclear weapon ever put through the development process (that the public knows about). And that honor is reserved for the Flashback Bomb.

So what exactly was this weapon? What was the historical context around it? And what can we lessons can we glean from its story? Let's take a look…

Table of Contents

  • 01

    The Nuclear Arms Race

  • 02

    The Birth of The Flashback Bomb

  • 03

    The (Alleged) Death of The Flashback Bomb

  • 04

    What Can We Learn from The Flashback Bomb

  • 05

    Frequently Asked Questions

The Nuclear Arms Race

One war leads to another, and that's precisely where the world found itself in the aftermath of World War 2. Though Hitler and Mussolini had been defeated, the valid threat of global communism and Joseph Stalin convinced the world that the fighting couldn't stop completely. The war against evil was still being fought. It had just changed flavors.

Thanks to the work of traitors and spies throughout America, the Soviets soon ended up with nuclear weapons. This in itself was concerning. But seeing the size of the weapons that Russia could produce generated the most fear. The world soon realized that Hiroshima and Nagasaki were peanuts compared to what nuclear weapons were actually capable of. And seeing that both Hiroshima and Nagasaki were the most significant man-made explosions in history, the knowledge that they were being made minuscule in comparison, particularly by a nation that wanted to wipe America off the face of the map, was cause for concern.

This came to a head with the detonation of the largest bomb the world had ever seen – the Tsar Bomba.

The Tsar Bomba

Andrei Sakharov was apparently somewhat conflicted with his occupation. Involved with making the most powerful nuclear weapon that the world had ever seen, he also seemed to have hesitations about the deaths future generations would face due to cancers caused by the radioactive fallout that he had primarily helped to create.

(Image courtesy of Andrei Sakharov)

Yet he continued to work, and on October 30, 1961, his work came to fruition as pilot Andre Durnovstev climbed into the cockpit of his Tupolev Tu-95 bomber.

The Tsar Bomba was absolutely massive. Just for the Soviets to be able to test it, they had to remove the bomb bay doors of the Tu-95 (which is a huge plane) and strap the Tsar Bomba into the little cavity underneath. It was a visually ridiculous setup, but it worked.

(Image courtesy of Russian Tu-95 )

As the plane flew off into the sky (alongside a Tu-16 tasked with filming the whole process), Durnovstev climbed into the sky at what he hoped was a safe cruising altitude and headed off deep into the Arctic Circle toward the Matochkin Strait. His destination? Novaya Zemlya is a small, forgotten, and frozen island not far from the North Pole.

As Durnovstev reached his target, the Tsar Bomba was released, and its parachute was deployed. This slowed descent gave the two plans at least a sliver of survival. Researchers had estimated a 50% chance that all members of the "Tsar Bomba pilots" would perish during the test. It would be interesting to discover if they ever told Durnovstev or the other crew members that statistic.

At 2.5 miles above the earth, the bomb detonated.

The shockwave traveled the world thrice, was detectable to New Zealand, and suddenly caused Durnovstev's plane to drop several thousand feet. The fireball was 5 miles wide, 37-43 miles high, and the flash could be seen from 621 miles away. All buildings within 34 miles of the explosion were vaporized, and windows shattered out hundreds of kilometers away.

And though this "unearthly spectacle," as Durnovstev would describe it showcased the most destructive potential mankind had ever known, leaving nothing but death and destruction in its wake, there was one thing that was borne of it: the desire for something even more prominent.

The desire for something such as The Flashback Bomb.


The Tsar Bomba was initially scheduled to be a 100 Megaton blast. Hiroshima and Nagasaki were 15 and 21 kilotons, respectively, in contrast. This was a bomb exponentially larger than both of those blasts combined. However, researcher Andre Sakharov was genuinely concerned about the potential impact that nuclear fallout would have on people for years to come.

So, he halved the megatonnage by halving his "recipe" for the Tsar Bomba. He'd created a new technique for nuclear weapons called "sloika," Russian for "layer cake." He would layer alternate layers of deuterium and uranium together for his material. To half this original 100 Mt payload, he substituted three layers of uranium with three layers of lead.

The Birth of The Flashback Bomb

While we outwardly expressed rage at the environmental impacts of the Tsar Bomba, we also knew that we had to compete. The Soviets could not be trusted when it came to making treaties, and history has proven this time and time again. During this stage in history, the Soviets breaking the 1961 Test Moratorium on nuclear weapons was a potent incentive to rapidly develop weapons that were just as powerful as the Tsar Bomba.

(Image courtesy of The Tsar Bomba explosion. )

Mutually assured destruction (MAD) was America's policy at the time, and if the Soviets threatened us with something the size of the Tsar Bomba, we would hit back even harder. We wanted something so substantial that it could crack open mountains. The Russians have long had secret military bunkers deep in the heart of the Ural Mountains, and we needed something that could assure that it didn't matter where you hid; if you threatened the United States, we would vaporize you.

And so we began researching and developing bombs that were 20x larger than the Tsar Bomba.


Nuclear war scientist Cresson Kearny noted in his book Nuclear War Survival Skills that one clear sign that Russia was preparing to launch a nuclear weapon was that their cities were being evacuated, and people were being moved to the many shelters scattered throughout the country.

It's worth noting that Russia is updating its fallout bunkers nationwide.

Several of these weapons were worked on, but the largest that we ever came close to fruition with was The Flashback nuclear bomb.

As expected, there is a mountain range of logistical hurdles when it comes to developing weapons that the world has never seen the likes of before. But slowly, step by step, we began to chisel away at problems to come up with solutions.

Part of these solutions may have come from scientist John Nuckolls. He created a new means of making absolutely massive bombs with lightweight "care" packages that were known as RIPPLE. We can't say for sure whether or not RIPPLE was used, but in some way or another, we made an absolutely massive bomb very quickly: The Flashback Bomb.

Nobody knows how big The Flashback Bomb payload was, but the bomb casing itself? Like the Tsar Bomba, it was so large that the bomb bay doors had to be removed from the B-52 Stratofortress that held it so it could be slung below.

(Image courtesy of B-52 Stratofortress)

But though the bomb was created, we ran into many issues with testing it. For starters, if you drop a bomb at least 20x more considerable than the Tsar Bomba, there's no hiding it. Aside from the blinding flash, the shockwave, and the seismic activity that just about anybody can detect, you will also end up with a lot of radioactive fallout. And where are you going to drop it? In the middle of the ocean somewhere? How large of a tidal wave will that create? How far will that tidal wave go? Will Hawaii appreciate being drenched in radioactive water?

As you can see, there were some issues here.

So, we settled for other research with The Flashback Bomb instead. In January 1965, a B-52 Stratofortress took off from Kirtland Air Force Base in New Mexico with a simulator in place where the warhead would typically be (we wanted to keep New Mexico). The plane flew to Oahu, Hawaii, then headed towards the Johnston Atoll (allegedly), where it conducted its research. Again, like the Tsar Bomba, a parachute pack was attached to the back of The Flashback Bomb to assist in the escape of future pilots. But unlike the Tsar Bomba, The Flashback Bomb wasn't necessarily created to detonate in the air. Instead, it was something known as a "laydown bomb."

(Image courtesy of Johnston Atoll)

Sandia National Laboratories developed this novel concept, arguably with many tactical advantages. Laydown bombs are slowed down on their descent to earth so that they do not break the sound barrier and can just lay down on the ground for an (indefinite?) period before detonation. Not only does this allow the pilot to have a better chance of escaping, but there may also be a chance that this serves as a new bargaining chip.

While there's no certainty about how long this delay was, it doesn't seem unreasonable to assume that this time could be programmed to be any time desired or that the bomb could simply be remotely detonated.

Imagine being to drop one of these down onto an enemy nation, monitor it via satellite, and then tell the enemy, "If anybody gets within this radius of the bomb, if anybody tries to jam our ability to communicate with it, and if you do not comply 100% with what we say, we push the button, and you're all destroyed."

It wouldn't be difficult to program this type of bomb to have a dead hand switch that would cause it to automatically detonate either if its radio signal was intercepted. The creation of this kind of device would be a way that one could effectively end a war before it ever started. You destroy one of our aircraft carriers? We drop a gigantic laydown bomb on your capital and tell you to cut it out and repay us.

But it was never meant to be (and perhaps that's a good thing).

The Flashback Bomb was doomed to the grave before it got the chance to be the doom of others.

The (Alleged) Death of The Flashback Bomb

Politics sang the swan song for The Flashback Bomb; as politics often is, it was a thorny issue. For starters, Eisenhower came out and publicly condemned the Tsar Bomba. While presidents are rarely above lying, it created a public relations issue for the researchers behind The Flashback Bomb.

If it were leaked that America was building a bomb 20+x larger than the Tsar Bomba (we know it was at least 50Mt, but it's theorized that this could have been 100+Mt. At the time, there was even discussion about creating giga-ton bombs. "Say goodbye to a continent" weapons.), it would have made some apparent public outrage and embarrassment knowing that our official stance was to disparage super high yield nuclear weapons.

Logistical and money problems were, of course, an issue. Still, it's argued that the final two nails in the coffin for The Flashback Bomb were A) fears that the leaked project would hinder future nuclear weapons treaties with the Soviets and B) the signing of The Limited Test Ban Treaty.

This treaty made it so we could no longer test nuclear weapons in the atmosphere, underwater, or space. If you wanted to test a nuke, The Limited Test Ban Treaty required that you do so underground, and the sheer logistics of this necessitated using a more minor explosion.

(Image courtesy of JFK signing the Limited Test Ban Treaty in 1963. )

Part of the reason that we were willing to sign the Limited Test Ban Treaty was that we had something of a workaround/backup plan called "Readiness to Test" at the ready. This plan made it so that should the Russians violate the treaty (again), we would be fully capable of testing bombs such as The Flashback Bomb within 90 days of the violation. Not only would this give us the ability to strike hard and fast, but the knowledge that we were doing this type of testing would act as a form of psychological warfare against the Soviets, causing them to think twice about further nuclear testing.

Nuclear war researcher Alex Wellerstein hypothesizes that America came to the conclusion that we could have either The Flashback Bomb (and others) or we could have The Limited Test Ban Treaty. And so, along with Russia and England, we signed the treaty.

Of course, like the Test Moratorium of 1961 that Russia broke, when you make a deal with a liar, don't be surprised when he doesn't honor it.

What Can We Learn from The Flashback Bomb

We can glean lessons from any period of history, and the development of The Flashback Bomb is no exception.

Perhaps the chief lesson that we can glean here is that when nuclear war breaks out, it will be like something the world has never seen, and even if your country isn't involved in the fighting, it will still experience the results.

The Tsar Bomba was said to have spread low radiation levels throughout all of Scandinavia, and it was detonated in the middle of nowhere. What would have happened had it been detonated over the center of a highly populated country? What would have happened had it just been one small drop in the bucket of how many nuclear weapons were used?

This is one reason that you should consider storing nuclear survival gear.

Should things with Ukraine progress further, one could easily see nuclear weapons being considered. It could quickly spark a daisy chain of nuclear events when that happens.

And if there's one thing that we can learn from the history of The Flashback Bomb, it's that secret weapons are secret because they are A) insanely powerful, and B) you don't want the world to know about them until the aftermath of their first use.

Witness the birth of ironclad ships during the Civil War, machine guns' impact on World War 1, the advent of the tank, the first use of chlorine gas on the battlefield, the terror that German dirigibles caused, or the birth of nuclear warfare. All of these were exceptionally powerful weapons, and they were kept more or less a secret until deployment.

"Mystify, mislead, and surprise the enemy," as Sun Tzu wrote in The Art of War. If you can achieve surprise, you have a massive tactical and strategic advantage over your opponent.

What surprises do America's enemies have in mind?

We highly recommend looking at our Nuclear Survival Kit as a result.

This kit contains several lifesaving pieces of gear: a high-quality gas mask, a filter that will protect you from radiation, and potassium iodide tablets to keep your thyroid from absorbing dangerous levels of radioactive iodine. In addition, the MIRA Safety Drop Leg Military Pouch is included, where you can store everything.

With this kit, you will have increased protection against thyroid cancer and be able to protect your lungs against the risk of breathing radioactive fallout.

You get your choice of one of two of our styles of gas masks as well. Our CM-6M is a great choice when a maximum range of vision is desired. For most American families, this is likely the option you would want to consider. Our CM-7M offers less wide a field of vision, but one advantage is that it's easier to shoulder a rifle and sight in a target without this mask's interference.

Buying these included components separately would cost you around $426 at the time of this writing. But if you purchase our Nuclear Survival Kit, you can get all of this for $370 at the moment. That's a substantial saving, making for an affordable means of upping your level of nuclear protection.

You need the ability to measure radiation.

Quite frankly, you have to have this if you want to survive the aftermath of a nuclear bomb. Nuclear war scientist Cresson Kearny thought the ability to detect and measure radiation was one of the most important steps to surviving a nuclear attack.

For this, we highly recommend the MIRA Safety Geiger-2 Portable Dosimeter/Geiger Counter. The design of this device is revolutionary. Slightly larger than a ballpoint pen, this device can be slipped into a pocket, tucked in a purse, or stowed away in any bag for rapid measurements (within 20 seconds) anytime, anyplace.

The sleek and straightforward two-button design of the Geiger-2 makes it simple enough that even a child won't have difficulties operating this device. Unlike other products, the Geiger-2 can detect down to 0.999 microsieverts/hour. You no longer have to be standing around in exceptionally high radiation levels before your dosimeter will alert you.

The Geiger-2 will give you the real-time information you need so that you can know for sure whether the recent improvements you just made to your fallout shelter are shielding you from radiation. You would have a better idea of when it is safe to leave a fallout shelter, how long you could leave it, and which areas are too dangerous to travel in.

The American organization Physicians for Civil Defense has repeatedly worked to boost the number of Geiger counters and dosimeters throughout the United States, knowing that these can potentially save millions of lives in the aftermath of a nuclear war.

Surviving a nuclear event not only takes food, shelter, water, and PPE. You have to be able to access updated information about what is safe and where it is not. Would that be because of a Tsar Bomba, Big Test Vehicle, or Flashback Bomb-sized nuke?

Most likely not. If there were a nuclear attack on American soil, it would probably be from something much smaller. But as we have seen simply from the events of 2022-2023, the specter of nuclear war is far from dead.

The Flashback Bomb is a Flashback to the Past

Though The Cold War is now considered over, in many ways, nothing really changed. The specter of nuclear warfare still hangs over the heads of Americans, and the Doomsday Clock, a means of measuring the world's risk of nuclear war, is closer to midnight than ever before.

And though we supposedly never completed The Flashback Bomb, it doesn't mean that neither we nor the rest of the world didn't complete other, smaller, yet massive nuclear weapons. Some secrets are best kept secret. We probably would prefer something else to how those discoveries would be made.

What are your thoughts on the matter? Do you have more to add to the story of The Flashback Bomb? Do we have planes now that could have held it without needing the bomb bay doors removed? Let us know what you think in the comment section below.

Frequently Asked Questions

Did we ever create anything larger than The Flashback Bomb?
Where can I learn more about The Flashback Bomb?
Would The Flashback Bomb destroy all life on earth?
What country has the largest nuclear bomb?
What would a 100-megaton bomb do?
What would a 1 gigaton nuke do?
Is there a nuke big enough to destroy the world?
How big would a nuke have to be to destroy the world?
Can the Tsar Bomba destroy a country?
How did Andrei Sakharov die?
Where is Novaya Zemlya?
What is mutually assured destruction?
How far does nuclear fallout travel?